Black Iron Pipe vs Black Steel Pipe


Different types of pipes are common in the plumbing industry. Among those, black iron and black steel pipes are standard.

They vary in terms of their properties, which makes them suitable for different purposes.

The differentiation in their purpose brings us to the black iron pipe vs black steel pipe comparison.

Both of these types serve their purpose efficiently. However, many people feel confused when choosing one of these two.

As you know, the wrong pipe selection can have a destructive impact on your project.

So, this guide will provide you with all the critical differences between them. Ultimately, you’ll be able to make informed decisions. So, let’s get started!

Overview of Black Iron Pipe

From the name, it seems this pipe is made up of iron. But that’s wrong, as its name is misleading. The black iron pipe consists of low-grade mild steel. It has a lower carbon content. However, it looks black in shape because of the iron coating.

A layer or coat of iron oxide is formed on the surface during manufacturing. This coating makes this pipe look black. What makes this pipe stand out is its strength. Many people prefer this pipe in plumbing work because it can withstand high pressure.

However, this pipe is prone to rust. Therefore, its durability is highly questionable. The manufacturer applies a coating to prevent rusting.

But this is a short-term solution. The black iron pipe has a maximum working pressure of 150 PSI. This makes it ideal for residential plumbing or gas lines.

Overview of Black Steel Pipe

Black steel pipe also consists of mild steel. However, it has a high carbon content, which makes the pipes very strong and reliable.

Just like an iron pipe, its color is black. The reason is that the iron oxide layer formed during the manufacturing process.

The black iron pipe comes in many pieces. The plumbers have joined the pieces through connectors.

However, the black steel pipes are welded and don’t need connectors. Therefore, their usage of supplying lines is more reliable. The chances of leakage are minimal when you use these black steel pipes.

The strength of these pipes is their excellent corrosion resistance. Even in harsh outdoor conditions, they hardly show any sign of rust. This is due to the zinc coating, which prevents rust formation. Moreover, its high carbon content also keeps it strong and rust-free.

Quick Info: The black iron pipes are old and outdated. Old houses made before the 1960s used this type of piping system. However, they are no longer keenly used for new construction projects. Black steel pipes are replacing these old pipes.

Black Iron Pipe VS Black Steel Pipe: 6 Key Differences

These two types of pipes differ in terms of purpose and usability. Apart from that, there are a few other distinctions as well. So, let’s discuss their critical differences in detail.

1- Composition and Manufacturing

Both of these pipes consist of mild steel. However, their proportion of carbon content varies in both of them. The black iron pipes consist of very low carbon content. On the flipside, the black steel pipes have higher carbon content. 

The manufacturing process of these pipes also varies from each other. The iron black pipes are produced through a hot rolling process. On the flip side, the black steel pipes result from a cold-forming process. Both of these manufacturing have their pros and cons.

2- Texture

The black steel pipes come with a very smooth surface. Their overall looks are also appealing due to the smooth surface. You won’t see any small cracks in these pipes. On the other hand, the black iron pipes are rougher in texture.

Although the lousy texture of black iron steel may be fine for many people. However, it affects the overall looks and physical appearance. The rough surface of black iron pipes encourages rust formation. This is one reason why plumbers prefer black steel pipes over iron.

3- Rust & Corrosion

Unfortunately, black iron pipes are prone to corrosion. When used in water pipelines, they get rusty internally and externally. Over time, the particles from internal rust add to the liquid they carry. The primary reasons behind this rust are the low carbon content and joints.

Black steel pipes show excellent rust resistance. They do not get rusty quickly; rust takes a very long time to appear on the surface. Manufacturers apply zinc coating to these pipes and galvanize them. This coating makes this type of pipe fight hard against rust.

4- Applications

Due to their different properties, the applications of these types are also different. For example, the black iron pipes have low working pressure. So, this pipe is commonly used in sprinkling systems. Moreover, their usage is common in gas distribution lines, etc.

Due to their strength, some plumbers use black steel pipes in harsh conditions. They are also rust-resistant and are employed in oil and gas transportation. Moreover, water lines and HVAC systems utilize this type of steel pipe.

Quick Note: The black steel pipes have a working pressure of 300 psi. This makes it suitable to carry different liquids and gasses from one point to another. You’ll see these pipes more often in water pipelines.

5- Repair & Maintenance

As I said earlier, the black iron pipe comes in pieces. The plumbers have to connect the pieces using connectors. But over time, these connectors start to leak. This becomes a headache once the piping system gets a bit old.

You’ll have to repair them again and again. Moreover, the connectors can also get rusty due to leakage. On the flip side, the black steel pipes don’t need connectors. So they don’t leak and don’t require any repairs.

6- Cost & Affordability

One of the major factors we consider is the price of the pipes. It would be correct to say that this factor is a deal-maker or breaker. So, the cost of black iron pipes is lower than that of their counterparts. They are a lot cheaper if you compare them with black steel pipes.

But the question is: Are black iron pipes worth it? I would say a big NO! The reason is that it is not rust-resistant. So, over time, you’ll have to replace them. If you don’t remove them, they will need regular maintenance and repair. It becomes a headache in the long run.

Keep in mind that regular repairs add additional cost. On the flip side, black steel pipes are rust-resistant and long-lasting. In the long run, they prove to be a more cost-effective option. All modern homes use black steel pipes.


It is no mistake that steel pipes are essential for our sustainability. Different types of pipes are available in the market.

However, many people, especially newbies, seem to be baffled about iron black and black steel pipes. This guide provides detailed insight and discusses their fundamental differences.